Here's how it might work:
1) As a guild leader: submit your guild to be added to main pool of guilds for a moderator to simply approve (to avoid spam)
2) Now, when gods make custom games, you can have an invitation for guilds to send. The list of guilds that appear will be those that have been approved by the moderator. When this invitation is sent, all guild members will get a notification to join the
custom match. Simple as that!

What this does is allow guilds to more easily grudge matches or even tournaments based around guilds, freeing up all of the mucking about with friends lists to get in on it. Just simply join a guild and every once in a while you'll get in on a guild game if you happen to be about when the invite fires.

The same moderator who accepts/declines guild submissions in step 1, could also have access to one of the front page splash screen ads. They could use this area to post results of tournaments held by the community members. Perhaps some system could be implimented were a guild who wins the previous tournament gets to make rules for the following tournaments. I had ideas that involved the ability for winners to write little blurbs about their guild's success, and even give the MVP of the tourney a spot to (this being optional, more on this stuff in the other thread)

But the idea here is to simply save time on coding automated systems, and just relegate the simple logistics of it to a moderator. If someone is able to moderate realms (lots of work) I don't see why we couldn't have someone moderate something as simple.

Even the special rules could be managed by the participants themselves. Say, if I break a certain rule in a big tournament, they could just be written off as disqualified...No biggie!

All of this said, I feel that something like this could really add to the feeling of an active community in a way that the numbers and charts for duel/league mode can't.